Gain or Loss on Sale of Investments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Available-for-sale
Proceeds from sales and calls of investment securities		$ 212,140	$ 167,660	$ 219,849
Gross realized gains	[1]	2,459	1,877	501
Gross realized losses	[1]	(3,794)	(1,808)	(705)
Held-to-maturity
Proceeds from calls of investment securities		25,405	20,997	8,930
Gross realized gains	[1]	97	50	22
Gross realized losses	[1]	$ (225)	$ (100)	$ (6)

[1] The gain or loss on the sale or call of each investment security is determined by the specific identification method.